RE: [Linux-cluster] GFS performance.

> -----Original Message-----
> From: linux-cluster-bounces redhat com
> [mailto:linux-cluster-bounces redhat com] On Behalf Of Ryan Golhar
> Sent: Monday, April 20, 2009 3:04 PM
> To: linux clustering
> Subject: Re: [Linux-cluster] GFS performance.
>
> This brings up an interesting question for me....We can 6
> machines that host a bunch of virtual machines. I'd like to
> put the virtual machines on a shared SAN disk. If one of the
> physical machines goes down, another one will take over and
> host a virtual machine.
Nice. If your virtualization is based on Xen, you can do live
migrations over shared storage. I've done it and it works well.
> Does it make sense to use GFS to manage the SAN then?
Perhaps I misunderstand, but I don't think there's a need for GFS unless
you also have shared filesystems.
In our setup each virtual machine has a (dedicated) root filesystem on a
SAN. They are all formatted with ext3, because they are not shared.
(We also have shared non-root volumes that are GFS.)
The decisions to virtualize your infrastructure with Xen (or equivalent)
and to share your filesystem storage with GFS (or equivalent) are
orthogonal considerations. You can successfully implement either, or
both. However, shared storage is useful to have either way.
Jeff